Multiple .onetoc2 OneNote files in SharePoint

Hello,

in SharePoint library (from Microsoft Teams) I have found multiple .onetoc2 OneNote files in a different folder in the SharePoint library.

Some of them are empty (cannot be opened), some of them can be opened (but they show only the structure - mirroring the structure of one SharePoint folder) and one of them contain the list and links to all OneNote files in SharePoint Library.

Any idea why and how were these documents created?

Kindest regards

Leon